Recent evidence of a potential role for cardiac progenitor cells (CPCs) in cardiac repair and the discovery of a vasoprotective axis of the renin-angiotensin system (RAS) offer such breakthroughs. Investigators have observed that an imbalance in the vasoprotective axis {angiotensin converting enzyme 2 (ACE2)/angiotensin-(1-7) [Ang-(1-7)]/Mas receptor} and the vasodeleterious axis [angiotensin converting enzyme (ACE)/angiotensin II (AngII)/AngII type 1 receptor (AT1R)] of the RAS within the CPCs affects their functionality and regenerative potential. Investigators believe that restoring the balance between these two axes of the RAS is essential to improve CPC function and enhance their reparative capabilities. These observations have led to the hypothesis that genetic modification of CPCs by overexpression of ACE2/Ang-(1-7) will enhance their reparative function and improve their potential to attenuate myocardial ischemia-induced cardiac damage.

As a participant undergoes a clinically indicated heart transplant, or a left ventricular assist device (LVAD) implantation, or a right heart biopsy, or atrial fibrillation surgery, or right atria cannulation, the following tissue samples will be collected:

In the subjects undergoing orthotopic heart transplant (n=20), failed myocardial tissue samples will be collected from the diseased heart.

For subjects undergoing left ventricular assist device implantation (n=60), small samples will be collected from the apex core (that would be routinely discarded at the time of the implantation procedure).

For heart transplant subjects undergoing clinically indicated right heart biopsy (n=20), the collection of multiple samples including, excess myocardial biopsy samples that will not be utilized by pathology.

For subjects undergoing any heart surgery (n=80), the collection of left atrial appendages that are routinely removed to prevent thrombosis during atrial fibrillation surgery and a piece of the right atria will be cut in order to implant the cannula.

In addition, a collection of 20ml (about one tablespoon) of blood will be taken from all subjects to analyze progenitor/inflammatory cells and inflammation cytokines and pertinent medical history.

Inclusion Criteria:

• heart transplant surgery
• left ventricular assist device implantation
• heart surgery required for atrial fibrillation and right atria cannulation

Exclusion Criteria:

• We are collecting discarded tissues following surgery. There is no exclusion criteria for this study.

Patients undergoing orthotopic heart transplant, left ventricular assist device implantation, right heart biopsy, and any other heart surgery (atrial fibrillation and right atria cannulation).